1. Field of the Invention
The present invention relates to a safety clamping device for a pull-cable in an aerial cableway, providing an overload protection between a pull-cable and a trolley of a cableway cabin.
2. Description of the Prior Art
Pull-cable sleeves have heretofore been disclosed as means of connection between the pull-cable and the trolley, some of these prior art pull-cables being anchored in an inner cone of such sleeves. Frequently because of improper casting of prior art clamping devices, water is able to penetrate the parts associated therewith and corrode the cable and clamp. Also, constantly reversing bending stresses of the separate wires during the spatial swinging of the pull-cable necessitates periodic inspection of the cable in such area which is a relatively expensive operation. The trolley cannot be shifted. Under such an arrangement, the position subjected to the greater risks is situated in the area of the end of cone, i.e., the area where the pull-cable frequently breaks, as shown by practical experience.
There are also known mechanical pull-cable clamps, that are equipped with a spring energy storage device or the like. The cable in the area of clamping is left in the original state when the mechanical pull-cable clamps are used. The trolley can be shifted on the pull-cable and the positions of increased susceptibility to cable breakage and corrosion are avoided.
On the other hand, the arrangement of two clamps on the trolley, as required by regulations, involves a stretching of the pull-cable between the two clamps, because of the tension, and of the two clamps one must transmit by far higher tension than it would be required on the basis of the downward-slope force of the trolley, so that further additional devices should be provided.